12 Most Beloved Star Trek: The Next Generation Episodes

When Setal, a Romulan defector, crosses the border into Federation space and claims that a Romulan invasion is imminent, Picard has to decide whether to take him at his word and risk an incursion into the Neutral Zone.

The Defector builds a palpable sense of suspense by giving us the exact amount of information that the crew has making us similarly unsure as to what the correct course of action is. Geordi mentions how one can never know the exact truth because one never possesses 100% of the facts and thus having to rely on instinct as well.

Guest star James Sloyan gives a passionate performance convincing us of Setal's sincerity while retaining that proud Romulan pride and patriotism. He mixes in disdain at having to deal with the Federation and desperation for them to listen to him. His presence also leads to some fresh interactions highlighting the personalities of the characters. Riker doesn't hide his doubts about him and is aggressive in his questioning while Data is curious and friendly.

There is also a third act twist that fits well with the established details while still retaining a measure of surprise. It also does a great job at emotionally ruining Setal as he learns he was played by the Romulan high command. For him to realize that all his sacrifices were for nothing is devastating giving the climax a strong emotional hook.

Containing one of the show's best guest appearances and a tense plot, The Defector will make a loyal viewer out of anyone.